Whence my mailboxes

Searched the forums and found similar problems but none that help me.

I updated to Mountain Lion and all my mailboxes are not showing in the verticle panel on the left side of the mail application.

The show/hide widget is set to show and my inboxes, sent, junk, trash mailboxes are visible.

However another 20 or so personal mailboxes are missing.

When I choose Mailbox > new mailbox > "on my mac" > import > "personal folders" I see the mailboxes. So, they still exist I hope, with their contents.

If I click on one, like "2012 orders" I get a dialog box asking what to name the new mailbox inside of "2012 orders".

But I don't want to create new ones, I want those existing ones visible in the mailbox panel like they were before the update to Mountain Lion.

Your suggestions are appreciated.